EPA Superfund Site

DONNA RESERVOIR AND CANAL SYSTEM

TX | EPA ID TX0000605363

About this site’s exposure pathways: As of September 2025, the Donna Reservoir and Canal System Superfund Site (Site) is currently designated as "Human Exposure Not Under Control" as a result of PCB-contaminated sediments and PCBs that are bioaccumulating and biomagnifying in fish tissue at the Site. The EPA completed the dredging of sediment in a half mile section of the canal with the highest concentrations of PCBs in May 2020. Over time the concentrations of PCBs should begin to decline but this will likely take a number of years. The EPA will continue to monitor PCB concentrations in sediment and fish tissue. The EPA will also coordinate with the Texas Department of State Health Services (TDSHS) to evaluate the risk from consuming fish caught within the Donna Reservoir and Canal System Superfund Site.

An Institutional Control (IC), in the form of an aquatic life order, has been implemented at the Site for a number of years. The TDSHS issued “Aquatic Life Order Number 9” in February 1994. This order stated that “. . . the Donna Irrigation System [Donna Site] located in Hidalgo County is declared a prohibited area for the taking of all species of aquatic life.” According to a sign posted by the Texas Department of Health, predecessor to the TDSHS, at Donna Lake there is a $500 fine for keeping fish from the reservoir and canal system. This sign also states that, “Warning, it is illegal to possess fish from this water, fish caught from this water may contain harmful chemicals.” The enforcement authority for this order is the Texas Parks and Wildlife Department (i.e., Game Wardens). The EPA expects that the TDSHS’s aquatic life order will remain in place until PCB levels in fish tissue are shown to have decreased to a level that is not an unacceptable risk.

Informational Institutional Controls (ICs) include the information distributed by the TDSHS concerning PCBs and the cooking options for fish caught from the Site. This document is titled “Guide on Fish Consumption and the Effects on Human Health” (Publication No. 09-14639, July 2015). To increase the awareness of the prohibitions concerning the taking of fish from the Site, the EPA will install and maintain warning signs for 5 years. The EPA plan includes enhanced outreach efforts conducted by the EPA, TDSHS, and other entities associated with the Site. These outreach efforts will emphasize that the prohibitions will remain in place after the remediation of the Site until the Remedial Action Objectives identified in the Record of Decision have been achieved.